GLACIAL POT-HOLES AT CROWN POINT, NEW YORK 463 
rim is smoothed and rounded off, and it has unmistakably under- 
gone great erosion and weathering since it was bored. 
At the foot of the cliff is the remnant of a still larger pot-hole 
that now forms a shallow niche in the face of the cliff, and com- 
prises the arcs of two intersecting circles with a combined diameter 
of 12 to.15 feet for the original pot-hole. The diameter of the 
smaller arc is computed to be 6.12 feet. Its depth is unknown, as 
it has never been cleared of the débris that fills it. 
Upham (31) describes a pot-hole in the Interstate Park at 
Taylor’s Falls in every way similar to this latter one. He suggests 
the hypothesis that it was formed partly in rock and partly in ice, 
and that when the ice melted away it was left in the imperfect form 
seen at present. The pot-hole described here, however, because of its 
proximity to another that shows unmistakable evidence of erosion, 
would seem to favor the hypothesis that it was bored in solid rock, 
and that, subsequently, the greater portion of it had been eroded 
away. Both pot-holes occur nearly at the top of a mountain, and 
are far from any stream bed. Their partial demolition after their 
formation supports Upham’s hypothesis that such pot-holes were 
formed during the early stages of the ice-sheet; but they can be 
equally well explained by the advance of a later ice invasion. 
March 17, 1913. 
BIBLIOGRAPHY 
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Preuss. Geol. Landesanst. Jahrb., p. 275, 1880. 
. Bonney, T. G. Ice Work, Present and Past, pp. 34-35, 1806. 
Story of Our Planet, 1893. 
. Bouvé, T. T. ‘Indian Pot-Holes or Giants’ Kettles of Foreign Writers,”’ 
Boston Soc. of Nat. Hist., Proc., XXIV, 219-26, 1889. 
7. Brégger, W. C., and Reusch, H. H. Geol. Soc. of London, Quar. Jotir., 
XXX, 750-71, 1874. 
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Dun PW NH 
